login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A218213 Number of n-digit primes representable as sums of consecutive squares. 2
1, 4, 13, 30, 69, 187, 519, 1401, 3889, 10861, 31640, 90735 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

There are no common representations of two, three or six squares for n < 13, so

a(n) = A218207(n) + A218209(n) + A218211(n); n < 13.

LINKS

Table of n, a(n) for n=1..12.

FORMULA

a(n) = A218214(n) - A218213(n-1).

MATHEMATICA

nn = 8; nMax = 10^nn; t = Table[0, {nn}]; Do[k = n; s = 0; While[s = s + k^2; s <= nMax, If[PrimeQ[s], t[[Ceiling[Log[10, s]]]]++];  k++], {n, Sqrt[nMax]}]; t (* T. D. Noe, Oct 23 2012 *)

CROSSREFS

Cf. A027861, A027862, A027863, A027864, A027866, A027867, A218207, A218209, A218211.

Sequence in context: A071400 A206806 A232228 * A075880 A042487 A154753

Adjacent sequences:  A218210 A218211 A218212 * A218214 A218215 A218216

KEYWORD

nonn,base

AUTHOR

Martin Renner, Oct 23 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified June 24 08:22 EDT 2017. Contains 288697 sequences.